EP2240295A2

EP2240295A2 - Coupling mechanism and method for automatically coupling a tool holder to a tool fixture on a manipulation device

Info

Publication number: EP2240295A2
Application number: EP09709185A
Authority: EP
Inventors: Helmut Ebner; Johann Penn; Johann Poeppl; Christian Schorn; Guoxin Shan; Suzanne Tanzer; Heinrich Thoene; Franz Wimmer
Original assignee: Siemens VAI Metals Technologies GmbH and Co; Siemens VAI Metals Technologies GmbH Austria
Current assignee: SIEMENS VAI METALS TECHNOLOGIES GMBH
Priority date: 2008-02-06
Filing date: 2009-01-16
Publication date: 2010-10-20
Anticipated expiration: 2029-01-16
Also published as: AT506365B1; WO2009097956A3; CN101939135A; KR20100113113A; AT506365A1; ATE531479T1; EP2240295B1; WO2009097956A2; CN101939135B

Abstract

The invention relates to a coupling mechanism for automatically coupling a tool holder (1) that supports a tool and comprises a conical shaft (11) and a clamping head (8) to a tool fixture (29) on a manipulation device (7). The tool fixture (29) comprises a conical sleeve (16) and a locking mechanism (2a) which encompasses a gripping device (2b) cooperating with the clamping head (8) and a clamping device (2c) acting in an axial direction. In order to allow very different tools and utensils to be automatically accommodated in a position-controlled manner, a number of sensors (31a, 31b, 31c, 32a, 32b, 32c) is arranged on the conical sleeve (16) of the tool fixture (2), and a reference surface (35) faces each sensor on the tool holder (2) in order to determine the position of the tool holder (1).

Description

description

Coupling device and method for automated coupling of a tool holder to a tool holder on a handling device.

Technical area

The invention relates to a coupling device for the automated coupling of a tool holder carrying a tool, which comprises a taper shank and a clamping head, on a tool holder on a handling device, such as preferably a robot. The toolholder is provided with a tapered sleeve and a locking mechanism comprising a gripping device cooperating with the clamping head and an axially acting clamping device. The coupling device is associated with a sensor for determining the position. Furthermore, the invention relates to a method for automated coupling of a tool-carrying tool holder on a tool holder on a handling device.

Under a tool-carrying tool holder is to be understood in a structurally very simple embodiment, a conical taper shank, which forms a manufacturing unit with a tool for performing certain work, preferably on a metallurgical device, such as a continuous casting or a melt container. For a specific application of a handling device in the area of a continuous casting plant, the tool holder according to a possible embodiment comprises a conical shank and a chuck, on which a tool, for example a measuring lance for determining the melt temperature in a distribution vessel or in the continuous casting mold or a free-blowing lance for opening the outlet opening of a melt vessel Positioned clamped on a storage surface in the area of action of the handling device is prepared.

State of the art

A device of the generic type is already known from DE 32 14 025 A1. Here, a cone sleeve-carrying part of this coupling device on the implement, such as a manufacturing robot, fixed fix. A equipped with a conical shank tool or any implement is stored in a tool magazine and the Robots can take different tools from the magazine by appropriate control and store them there again. The locking of the implement in the tapered sleeve takes place here by a hydraulically or pneumatically actuated locking bolt which engages in the locking position in a recess of the conical shank. Further details on the targeted approach of the locking position by the robot can not be found in this document.

DE 33 36 111 C1, DE 20 2005 013 995 U1, DE 101 41 641 A1 and DE 297 23 331 U1 are power-operated clamping and releasing devices for shank tools, known as steep taper tools, in which a tool with a conical shank and a chuck inserted into a tapered sleeve of a tool carrier or a work spindle and with an axially movable tie rod, the clamping elements are assigned, pulled into the tapered sleeve and held in it.

Tools equipped with these described dome devices are predominantly used in machine tools and usually require special tuning with the gripper of a tool changer, which facilitates the transport of the tool between a magazine and the e.g. Working spindle of the machine tool perceives.

The use and application of position measuring sensors in coupling devices and in a method for monitored coupling of a tool to a tool holder are already known from several documents.

The use of a position measuring sensor in the usual insertion of a tool into a tool holder and its use for monitoring this insertion process is described in WO 2004/037486 A1. However, this solution with one independently of the parts to be coupled fixedly positioned sensor is not suitable for monitoring a Ankuppelvorganges on a tool holder a handling device, such as preferably a robot, because of the prevailing three-dimensional motion sequences.

Sensors for checking the position of a tool in the assumed coupled state with regard to the concentricity of the tool or a proper locking of the tool in a tool chuck are already known from DE 44 15 306 A1 and EP 1 726 401 A1. These embodiments of a device for Checking a mounting position are also not suitable to control a dome operation.

Presentation of the invention

Object of the present invention is to avoid the disadvantages of the known prior art and to propose a device and a method of the type described above, in which an automated recording a variety of tools and implements position-controlled is possible.

The object underlying the invention is achieved with a device of the type described above in that a number of sensors are arranged on the conical sleeve of the tool holder, and each sensor has a reference surface on the tool holder for determining its position. The sensors detect their distance from the associated reference surface, or generate a signal corresponding to this distance.

In order to protect the conical shank of the tool holder in its area of use from external influences, such as in particular from contamination and intense thermal load, for example, liquid metal in metallurgical vessels without hindering the inclusion of a tool-carrying tool holder, it is provided that the conical shank of the tool holder of a protective cover surrounding the conical shank along its longitudinal extent with a radial spacing is surrounded.

Favorable conditions for the picking operation of a tool by a handling device is given when the reference surface on the tool holder is formed by the outer conical surface of the conical shank.

Particularly favorable conditions for the recording process of a tool are given when the reference surface is formed on the tool holder of the inner circumferential surface of the conical shaft with a radial distance enveloping protective hood.

For unambiguous determination of the spatial position of the tool holder relative to the spatial position of the tool holder, it is necessary for a plurality of sensors to be arranged on the inner conical surface or on the outer wall of the conical sleeve are, and that these sensors are assigned to an evaluation of the determined measurement data and the evaluation is signal-technically connected to adjusting the handling device.

Preferably, at least two, preferably three, sensors are arranged on the inner conical surface or on the outer wall of the conical sleeve in a first plane oriented normally on the longitudinal axis of the tool holder and second in a further axial distance to the first plane and normal to the longitudinal axis of the tool holder Level at least one other sensor is arranged.

The arrangement of three sensors is sufficient to determine the position of the tool holder relative to the tool holder in the axial direction of the longitudinal axis of the tool holder or the tool holder and a fourth sensor is necessary to determine the tilt angle of the tool holder to the tool holder.

The sensors may be based on different known measuring systems. It can be used both inductive, capacitive or optical sensors for distance measurement.

For tools that have to assume a certain angular position in the tool holder for their appropriate use, it is advantageous if this purpose a desired target position is already determined during the recording of the tool holder by the tool holder. This is achieved by associating the conical shank and the conical sleeve with corresponding locking elements. This desired target position is determined when the conical shank a projecting or protruding from the lateral surface locking element, such as a key, and the conical sleeve of the tool holder a corresponding, an angular position determining locking opening, for example, a groove assigned.

For special applications tools are needed, which must perform in addition to their positioning or adjusting movement functions that can not be performed directly by the handling device such as the gripping movements of a pair of pliers. To make this possible, is located in a locked position of the tool holder in the tool holder an outlet opening of a Media supply line on the conical surface of the conical sleeve of an outlet opening of a media supply line to the conical surface of the conical shank opposite.

If a plurality of corresponding media supply lines are necessary for actuating the tool, these corresponding media supply lines are separated from one another by sealing elements in the arrangement of a plurality of outlet openings on the conical sleeve and on the conical shaft.

To achieve the object is further a method for automated coupling of a tool-carrying tool holder on a tool holder on a handling device, such as preferably a robot, which is characterized in that a mounted in a storage position in a tool holder tool selected by the control unit of the handling device and is driven or approached by the tool holder that during the pushing of the tool holder on the tool holder, the actual position of the tool holder is continuously determined and corrected for sensors with sensors and fixed that the tool holder in its reached target position of a gripping and clamping device of the tool holder in the tool holder becomes.

The determination of the actual position of the tool holder relative to the tool holder is carried out with a plurality of sensors distributed on the tool holder, which is a representative of the distance to a reference surface on the tool holder measurement signal is taken that from these measurement signals, the radial deviation and the tilt angle of the tool holder is determined to the tool holder and at least one control signal is generated with the alignment of the tool holder on the tool holder by adjusting means of the handling device. Instead of the radial deviation and the tilt angle of the tool holder to the tool holder and other, the spatial assignment of the tool holder to the tool holder clearly defining characteristics can be determined.

An asymmetrical arrangement of the sensors makes it possible to additionally determine the angular position of the tool holder relative to the tool holder from the measuring signals recorded by the sensors and to generate a control signal with which the spatial alignment of the tool holder takes place through the adjusting means of the handling device. Brief description of the drawings

Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the attached figures, which show:

1 shows a longitudinal section through a coupling device according to the invention with a tool holder and with a tool holder,

2 is a functional diagram for automatic coupling with the coupling device according to the invention,

Fig. 3a, the geometric relationships during the coupling process in a

Longitudinal view through the tool holder and the tool holder,

Fig. 3b, the geometric relationships during the coupling process in one

Projection into an image plane normal to the longitudinal axis of the toolholder,

Fig.4 illustration of the media supply passage through tool holder and tool holder.

Embodiment of the invention

1 shows a coupling device for the automated coupling of a tool holder 1 to a tool holder 2 of the type according to the invention in a longitudinal section through the coupling device. On the tool holder 1 is not shown in detail, indicated by dash-dotted lines tool 3 frontally attached. The tool holder 2 is connected to the end face 4 of a connecting flange 5 to a direction indicated by dashed lines connecting flange 6 of a boom 7 a handling device, not shown, for. B. a multi-axis robot, connected.

The tool holder 1 comprises a clamping head 8 with a flange 9, on which a tool 3 is fixed for performing work, and a flange 10 which is fixedly connected to a conical shank 11. This conical shank 11 is found with the same dimensions on all tools used on the handling device become. This makes a simple and quick replacement of tools possible. The front side of the conical shaft 11 is a draw bolt 12 associated with a mushroom-shaped head 13 and an annular groove 14.

The tool holder 2 comprises a housing 15a and an end face flanged to this housing, flared outwardly tapered sleeve 16 whose inner conical surface 16a has the same slope as the outer conical surface 11a of the conical shank 11. The core component of the tool holder 2 is a locking mechanism 2a, the a gripping device 2b and a clamping device 2c. Attached to a support flange 17 is the tensioning device 2c formed by a pressure medium cylinder unit 18, which comprises a piston 19 and a multi-part piston rod 20, which is displaceable along the longitudinal axis 21 of the tool holder. On the piston rod 20 a plurality of tongues designed as springs 22 are fastened with its one end and movable with its other end in the radial direction. The clamping tongues 22 have locking lugs 23 at their movable ends, which allow an axial movement of the mushroom-shaped head 13 as far as the stop surface 24 of the piston rod 20 when threading the tool holder 1 into the conical sleeve 16. In the axial locking movement of the piston 19, the clamping tongues 22 are pressed on the conical surface 26 of the centering sleeve 27 inwardly, engage in the annular groove 14 of the tension bolt 12 and clamp the taper shank 11 centrally in the conical sleeve 16, so that the longitudinal axis 21 of the tool holder. 2 aligned with the longitudinal axis 28 of the tool holder.

The tool holder 1 is surrounded along its longitudinal extent by a tubular protective hood 29, which is fastened with its one end to the flange 9 and is open in the direction of the tool holder 2. The protective cover 29 forms a cylindrical protective covering for the conical shank 11 and the draw bolt 13, as well as in the coupled position for the conical sleeve 16 of the tool holder 2 in order to protect these parts against thermal influences and contamination in the working area of the handling device.

In the outer wall 30 of the conical sleeve 16 of the tool holder 2 a plurality of sensors 31a, 31b, 32a, 32b are arranged distributed in two normal planes E1 and E2 on the circumference, with which a representative of the distance to a reference surface 35 of the tool holder 1 measurement signal can be determined , The reference surface 35 is in this case formed by the inner circumferential surface 34 of the tubular protective cover 29, such as 2, the measurement signals are fed continuously or at intervals to an evaluation unit 37 in which each sensor is assigned a minimum distance value corresponding to the measurement signal to the reference surface 35 and, taking into account the spatial positions of the sensors, the relative position of the tool holder 2 to the position of the sensor Tool holder 1, thus the parallel offset and the spatial inclination of the longitudinal axis 21 of the tool holder 2 to the longitudinal axis 28 of the tool holder 1 determined. From these determined actual values actuating signals are generated, which are supplied to the adjusting means 38 of the handling device 7, ie with the handling device, the cone sleeve 16 of the tool holder 2 sensor-aligned on the conical shaft 11 of the example provided in a magazine tool holder 1 aligned and slid. The handling device 7 is assigned a control unit 46, which controls the selection of a tool mounted in a tool holder from a storage position, not shown, of a tool magazine and the movement sequence of the tool holder 2.

3a and 3b show a momentary situation during the automated Ankuppelvorganges in a longitudinal section in Figure 3a and projected onto an image plane in Figure 3b in view of the longitudinal axis 21 of the tool holder 2. The tapered sleeve is cut by two normal normal planes E ₁ and E ₂ , the in Figure 3b by the lines of intersection with the outer conical surface 30 are formed and circles (solid lines) with the radii R _E1 and R _E2 form, which lie on a normal to the image plane longitudinal axis 21 of the tool holder and are projected into the image plane. On these radii, the sensors 31a, 31b, 31c, 32a, 32b, 32c are distributed around the circumference. In an instantaneous position during the sliding of the conical sleeve onto the conical shank, the two normal planes E ₁ and E _{2 result in} intersection lines e ₂ e ₂ with the inner circumferential surface 34 of the protective cover 29, which form ellipses (dashed lines). The radial distance r _{E1 1} , r _{E1 2} , r _{E1 3} , r _{E2 and} _E22 , r _E23 of the respective sensors 31a, 31b, 31c, 32a, 32b, 32c to the respective section line e _u e _{2 of} the inner circumferential surface 34 of Protective hood corresponds to the distance detected by the sensors to the reference surface 35. Intersecting points of the image planes E ₁ and E ₂ projected into the image plane with the longitudinal axis of the tool holder represent two points of the longitudinal axis of the tool holder and show the axial offset of the two longitudinal axes. From the longitudinal section of Figure 3a, the tilt angle a of the two longitudinal axes 21, 28 is visible to each other. With a sufficiently large number of sensors is a complete determination of all the necessary parameters for a position control by the Handling device in a mathematical model possible, which describes the geometric relationships of the spatial position of the tool holder and the tool holder to each other.

For the specific case that a tool is associated with the tool holder, which has to perform, for example, gripping, clamping and holding movements, as is the case with pliers, a media supply line 40 (compressed air, signal lines) through a contact area of the tool holder and the Tool receiver led. A suitable arrangement is shown in Figure 4. In the locked position of the tool holder 1 in the tool holder 2 is an outlet opening 41 of the media supply line 40 in the conical surface 16 a of the cone sleeve 16 an outlet opening 42 of the media supply line 40 in the conical surface 11 a of the conical shank 11 opposite.

A plurality of juxtaposed, corresponding outlet openings 41, 42, 41a, 42a on the conical sleeve 16 and the conical shaft 11 are separated from each other by sealing elements 43. The sealing elements 43 are formed by O-rings, which are inserted in annular grooves 44 of the conical shank 11. It is alternatively also possible that the O-rings are inserted in annular grooves on the tapered sleeve.

LIST OF REFERENCE NUMBERS

toolholder

Tool receiver a Locking mechanism b Gripping device c Clamping device

Tool, 5, 6 connection flange

Boom of a handling device

Clamping head, 10 Flange 1 Taper shank 1a Tapered surface of conical shank 112 Tension bolt 3 mushroom-shaped head of tensile bolt 124 Ring groove 5a Housing 6 Taper sleeve 6a Inner conical surface of tapered sleeve 167 Support flange 8 Pressure medium cylinder unit 9 Pistons 0 Multi-part piston rod 1 Longitudinal axis of tool holder 22 Tensioning tongue 3 Locking nose of tensioning tongue 22

Stop surface on the piston rod 206 conical surface 7 centering sleeve 8 longitudinal axis of the tool holder. 1

guard

Outer wall of the cone sleeve 1a, 31 b, 31c sensors a, 32b, 32c sensors 34 inner lateral surface of the protective cover 29

35 reference surface

37 evaluation unit

38 adjusting means of the handling device

40 media supply line

41, 41 a, 42, 42 a outlet opening of the media supply line 40

43 sealing element

44 annular groove for sealing element 43

46 control unit

a tilt angle

Egg, E ₂ normal levels

REI> RE2 radii in the normal plane βi, 'e ₂ cutting lines

("El 3,

I "E2 1 i I" E2 2> I * E2 3 Radial distance sensor - S

Claims

Claims:

1. coupling device for the automated coupling of a tool-carrying tool holder (1) comprising a conical shank (11) and a clamping head (8) to a tool holder (2) on a handling device (7), such as a robot, with a conical sleeve ( 16) and a locking mechanism (2a), which comprises a gripping device (2b) cooperating with the clamping head (8) and a tensioning device (2c) acting in the axial direction, and a sensor for position determination, characterized in that on the conical sleeve (16 ) of the tool holder (2) a number of sensors (31a, 31 b, 31c, 32a, 32b, 32c) are arranged and each sensor a reference surface (35) on the tool holder (1) opposite to its position determination.

2. coupling device according to claim 1, characterized in that the conical shank (11) of the tool holder (1) by a conical shaft (11) along its longitudinal extent with a radial distance enveloping protective cover (29) is surrounded.

3. coupling device according to claim 1 or 2, characterized in that the reference surface (35) on the tool holder (1) from the outer conical surface (11 a) of the conical shank (11) is formed.

4. Coupling device according to claim 1 or 2, characterized in that the reference surface (35) on the tool holder (1) of the inner circumferential surface (34) of the cone shank (11) with a radial distance enveloping protective hood (29) is formed.

5. Coupling device according to one of the preceding claims, characterized in that on the inner conical surface (16 a) or on the outer wall (30) of the conical sleeve (16) a plurality of sensors (31 a, 31 b, 31 c, 32 a, 32 b, 32 c) for determining spatial position of the tool holder (1) relative to spatial position of the tool holder (2) are arranged, that the sensors (31a, 31b, 31c, 32a, 32b, 32c) of an evaluation unit (37) for the determined measurement data is assigned and the evaluation unit (37) with adjusting means (38) of the handling device (7) is connected by signal technology.

6. coupling device according to claim 5, characterized in that on the inner conical surface (16 a) or on the outer wall (30) of the conical sleeve (16) at least two, preferably three, sensors (31 a, 31 b, 31 c) in a normal to the longitudinal axis (21) of the tool holder (2) aligned first plane (E1) are arranged and in a further axially spaced from the first plane (E1) and normal to the longitudinal axis (21) of the tool holder (2) aligned second plane (E2) at least one another sensor (32a, 32b, 32c) is arranged.

7. Coupling device according to one of the preceding claims, characterized in that the sensors (31a, 31b, 31c, 32a, 32b, 32c) are formed by inductive, capacitive or optical sensors.

8. coupling device according to one of the preceding claims, characterized in that the conical shank (11) and the conical sleeve (16) are associated with corresponding locking elements.

9. coupling device according to claim 8, characterized in that the conical shank (11) is associated with a feather key and the conical sleeve (16) has a corresponding groove for fixing the angular position of the tool holder in the tool holder.

10. Coupling device according to one of the preceding claims, characterized in that in a locked position of the tool holder (1) in the tool holder (2) has an outlet opening (41) of a media supply line (40) on the conical surface (16a) of the conical sleeve (16) of an outlet opening (42) of a media supply line (40) on the conical surface (11a) of the conical shank (11) opposite.

11. Coupling device according to claim 10, characterized in that corresponding media supply lines (40, 40 a) in the arrangement a plurality of outlet openings (41, 42, 41a, 42a) on the conical sleeve (16) and the conical shank (11) by sealing elements (43) are separated from each other.

12. A method for automated coupling of a tool-carrying tool holder (1) on a tool holder (2) on a handling device (7), such as a robot, characterized in that in a storage position in a tool holder (1) mounted tool from the control unit (46) of the handling device (7) is selected and controlled by the tool holder (2) that during the pushing of the tool holder on the tool holder, the actual position of the tool holder to the tool holder with sensors (31a, 31b, 31c, 32a, 32b, 32c) determined continuously and is corrected and that the tool holder is fixed in its reached target position of a gripping and clamping device (2b, 2c) of the tool holder in the tool holder.

13. The method according to claim 12, characterized in that for determining the actual position of the tool holder (1) relative to the tool holder (2) with a plurality of sensors distributed on the tool holder arranged (31a, 31 b, 31 c, 32 a, 32 b, 32 c) for the distance to a reference surface (35) on the tool holder (1) representative measurement signal is recorded that from these measurement signals, the radial deviation and the tilt angle («) of the tool holder is determined to the tool holder and at least one control signal is generated with the orientation of the tool holder the tool holder by adjusting means (38) of the handling device (7).

14. The method according to claim 12 or 13, characterized in that additionally determined from the sensors (31a, 31b, 31c, 32a, 32b, 32c) measuring signals, the angular position of the tool holder (1) to the tool holder (2) and a control signal is generated, with which the spatial orientation of the tool holder (2) by the adjusting means (38) of the handling device (7).